Adjustable socket mountings for fluorescent lighting fixtures

ABSTRACT

An elongated socket-supporting element, for assembly in a fluorescent lighting fixture, to adjustably support a plurality of fluorescent lamp sockets. The socket-supporting element is provided with a plurality of elongated, aligned, spaced-apart socket guide holes and has a slidable plate, provided with a fluorescent lamp socket, covering each hole. The slide plates can be shifted toward and away from each other to receive lamp terminals of various spacings. More particularly the device is applicable for adjusting the socket spacings in the socketsupporting element to accommodate the various terminal spacings of conventional U-shaped, hot-cathode fluorescent lamp tubes.

United States Patent [72] inventor Melbourne C. Reeves Denver, Colo.

[21 Appl. No. 763,822

[22] Filed Sept. 30, 1968 [45] Patented Feb. 9, 197] [7 3 AssigneeSechrist Corporation Denver, Colo. a corporation of Delaware [54]ADJUSTABLE SOCKET MOUNTINCS FOR FLUORESCENT LIGHTING FIXTURES 3 Claims,6 Drawing Figs.

[52] U.S. Cl 240/5l.l2

[5 1] Int. Cl l l-l05b 33/02 [50] Field ofSearch 339/50, 5 l

52,53, 54, 55,56; 240/5l.ll, li.4,5l.l2

[56] References Cited UNITED STATES PATENTS 2,399,531 4/1946 Young 240/51.11 3,263,201 7/1966 Pistey 339/52 Primary Examiner-John M. HoranAssistant Examiner-Kenneth C. l-lutchison Attorney-R. l-l. GalbreathABSTRACT: An elongated socket-supporting element,for assembly in afluorescent lighting fixture, to adjustably support a plurality offluorescent lamp sockets. The socket-supporting element is provided witha plurality of elongated, aligned,

spaced-apart socket guide holes and has a slidable plate, provided witha fluorescent lamp socket, covering each hole. The slide plates can beshifted toward and away from each other to receive lamp terminals ofvarious spacings. More particularly the device is applicable foradjusting the socket spacings in the socketsupporting element. toaccommodate the various terminal spacings of conventional U-shaped,hot-cathode fluorescent lamp tubes.

ADJUSTABLE SOCKET MOUNTINGS FOR FLUORESCENT LIGHTING FIXTURESFluorescent lamp tubes for ceiling fixtures are usually of the straightlinear type with pairs of terminal pins projecting from each of theopposite extremities of the tube. The fixtures are usually designed withan aligned row of fixed conventional tube sockets at each extremity ofthe fixture for receiving the terminal pins so that the tubes willextend between the row of sockets in parallel spaced relation. Since thespacing between the sockets in the rows is fixed by the fixture designerat the time of manufacture, no changes can be made therein should adifferent spacing of tubes be later desiredv The principal object ofthis invention is to provide an efficient socket mounting element foruse in the assembly of fluorescent lighting fixtures which will providean aligned plurality of sockets which can be quickly and easily adjustedwhen in place and without the use of tools to provide any desiredspacing between the tubes of the fixture.

A more recent development in fluorescent lighting tubes is a U-shapedtube, which is bent back upon itself to produce two parallelspaced-apart legs each terminating in a pair of conventional terminalpins. Such tubes require only one row of sockets in the fixture, butfixedly spaced sockets, as formerly used, are proving unsatisfactory dueto the fact that, as yet, it is difficult to obtain U-tubes having auniform, accurately preset spacing between the tube extremities. Tubesof different makes and even tubes of the same make will sufficientlyvary in spacing so that the terminal pins are frequently not insertablein two fixedly spaced sockets.

A further object of this invention is to provide a socket mountingelement for U-shaped tubes which will enable the tube-receiving socketsto be quickly and easily spaced to suit each particular U-tube, at thetime of insertion of the latter, so that spacing variations in the tubeswill be of no consequence.

A further object is to provide a quickly adjustable socket spacing meansfor fluorescent tube fixtures which will accurately maintain the socketsin their proper radial pin-receiving positions at all adjusted positionsand which will maintain all of the socket elements tightly springpressed to avoid all looseness and vibration.

Other objects and advantages reside in the detail construction of theinvention, which is designed for simplicity, economy, and efficiency.These will become more apparent from the following description.

In the following detailed description of the invention, reference ismade to the accompanying drawing which forms a part hereof. Likenumerals refer to like parts in all views of the drawing and throughoutthe description.

In the drawing:

FIG. 1 is a fragmentary, vertical, elevational view of a portion of theinner face of the fluorescent socket-supporting element ofthisinvention;

FIG. 2 is a similar elevational view of the outer face of thesocket-supporting element of FIG. 1;

FIG. 3 is a top view thereof;

FIG. 4 is an enlarged, vertical cross section taken on the line 4-4,FIG. 1 with adjacent parts of the conventional fixture shown in brokenline;

FIG. 5 is a detail perspective view of a slide plate employed in thesocket supporting element to be later described; and

FIG. 6 illustrates a conventional U-shaped fluorescent lamp tube towhich the invention is particularly adaptable.

In the drawing, a conventional U-shaped type of fluorescent tube isdesignated by the numeral 10 with its pair of terminal pins at 11. Thesocket supporting element, below described, is applicable to any type offixture. The fixture, per se, forms no part of the present invention butfor the purpose of showing the relative position of the invention in aconventional fixture, a fixture top plate and a fixture end plate areindicated in broken line in FIG. 4 and designated by the numerals l2 and13, respectively.

The socket supporting element comprises a horizontally elongated sheetmetal plate which is transversally preformed to provide: a verticalsocket-supporting portion 14; a forwardly extending top portion 15; anda rearwardly extending bottom portion 16. The forwardly extending topportion is designed to be attached to the fixture top plate 12, by aplurality of wing bolts 17 extending through slotted bolt holes 31 inthe top portion. The bottom portion 16 is connected to the fixture endplate 13, in any suitable manner, to support the socket-supportingportion 14 at the ends of, and at right angles to the axes of, thefluorescent tubes of the fixture.

The socket-supporting portion 14 is provided with a plurality ofspaced-apart, horizontally elongated and horizontally aligned, socketguide holes 18, of less height than width, behind each of which a slideplate 19, as shown in FIG. 5, is positioned. The slide plates are formedfrom resiliently flexible sheet metal and are similar in size and shape.Each slide plate is of greater height and width than the guide holes 18in the vertical portion 14. Each is provided with a forwardly extendingtop flange 20, which slidably overlaps the rear edge of the top portion15, and a rearwardly extending bottom flange 21, which slidably rides onthe bottom portion 16. Each slide plate is provided with a mediallypositioned, round, socket opening 22 of a diameter to closely receiveany suitable conventional fluorescent tube socket assembly.

A tube socket assembly which has been found to be very satisfactory forthe present purposes is commercially known as Leviton 0518 Snap-OnSocket. The latter socket consists of an insulated, cylindrical baseblock 23 having a circular escutcheon plate 24 of larger diameter thanthe base block on its forward extremity. A tube contact plunger 25,provided with a pair of tube pin openings 26, projects resilientlyforwardly from each of the base blocks through its respective escutcheonplate 24, to receive the terminal pins of the fluorescent tube. Anannular series of arched, spring fingers 27 project rearwardly from theescutcheon plate 24 to lock the base block in a conventional socketreceiving opening and the block is provided with a projecting key 28 toprevent rotation of the block in its respective receiving opening.

The above described tube socket assemblies are installed in thisinvention by placing each individual slide plate rearwardly of one ofthe socket guide holes 18 then forcing the socket base blocks 23rearwardly in the socket openings 22 of the slide plates with the keys28 engaging in key notches 29 formed in opening 22. The forcing iscontinued until the fingers 27 snap radially outward behind the slideplate to constantly and resiliently urge the escutcheon plate 24rearwardly into frictional engagement with the face of thesocket-supporting portion 14 above and below their respective socketguide holes 18, as shown in FIGS. 2 and 4.

The keys 28 prevent rotation of the sockets in their respective slideplates and the top and bottom flange 20 and 21, respectively, preventrotation of the slide plates 19 so that the pin openings 26 will alwaysbe in the proper radial position to receive the tube terminal pins 11 atall horizontal positions of the sockets. The socket wiring isconventional except that the leads must be sufficiently long to allowfor the extreme horizontal movement of the sockets.

It can be seen from the above that the socket assemblies can be manuallymoved horizontally, against the frictional bias between the escutcheonplates and the portion 20, for the full length of the horizontallyelongated socket guide holes 18 so as to accommodate any desired spacingof straight fluorescent tubes or any variations in the spacing betweenthe terminals of U-shaped tubes 10. It will be noted that the side edgeof each slide plate is bent slightly away from the vertical portion 14to form an outwardly inclined, overriding edge 30 thereon. This is toenable the slide plates to override each other should adjacent socketsbe brought relatively close to each other as shown by the two right-handsockets in FIGS. 1, 2 and 3.

While a specific form of the invention has been described andillustrated herein, it is to be understood that the same may be variedwithin the scope of the appended claims, without departing from thespirit of the invention.

[claim An adjustable socket mounting for fluorescent lighting fixturescomprising:

a. a vertical, horizontally elongated socket-supporting plate; b. aplurality of horizontally elongated, horizontally aligned,

. a fluorescent tube socket assembly fixedly mounted in each of saidsocket openings and projecting forwardly through the socket guide hole;

. an escutcheon plate having a greater vertical width than said guideholes forwardly mounted on each socket assembly so as to frictionallyengage the forward face of said socket-supporting plate; and

g. means on said socket assembly acting to urge said slide plateforwardly into frictional engagement with the rear face of saidsocket-supporting plate.

2. An adjustable socket mounting for fluorescent lighting fixtures asdescribed in claim 1 in which the means acting to urge said slide plateforwardly comprises an annular series of spring fingers surrounding saidsocket assembly rearwardly of said escutcheon plate and positioned toresiliently engage said slide plate and acting-to simultaneously urgethe slide plate forwardly and the escutcheon plate rearwardly.

3. An adjustable socket mounting for fluorescent lighting fixtures asdescribed in claim 1 having one side extremity of each slide platearched rearwardly from said socket-supporting plate the other sideextremity being nonarched so that when two adjacent slide plates arebrought into engagement with each other the arched side of one platewill override the nonarched side of the other plate to allow said socketassemblies to closely approach each other.

1. An adjustable socket mounting for fluorescent lighting fixturescomprising: a. a vertical, horizontally elongated socket-supportingplate; b. a plurality of horizontally elongated, horizontally aligned,spaced-apart socket guide holes formed in said plate; c. a slide platepositioned in horizontally slidable engagement with the rear face ofsaid socket-supporting plate back of each of said guide holes so as tooverlap the rear face of said socket-supporting plate and close itsrespective guide hole; d. a socket-receiving, medially positioned,socket opening in each of said slide plates; e. a fluorescent tubesocket assembly fixedly mounted in each of said socket openings andprojecting forwardly through the socket guide hole; f. an escutcheonplate having a greater vertical width than said guide holes forwardlymounted on each socket assembly so as to frictionally engage the forwardface of said socket-supporting plate; and g. means on said socketassembly acting to urge said slide plate forwardly into frictionalengagement with the rear face of said socket-supporting plate.
 2. Anadjustable socket mounting for fluorescent lighting fixtures asdescribed in claim 1 in which the means acting to urge said slide plateforwardly comprises an annular series of spring fingers surrounding saidsocket assembly rearwardly of said escutcheon plate and positioned toresiliently engage said slide plate and acting to simultaneously urgethe slide plate forwardly and the escutcheon plate rearwardly.
 3. Anadjustable socket mounting for fluorescent lighting fixtures asdescribed in claim 1 having one side extremity of each slide platearched rearwardly from said socket-supporting plate the other sideextremity being nonarched so that when two adjacent slide plates arebrought into engagement with each other the arched side of one platewill override the nonarched side of the other plate to allow said socketassemblies to closely approach each other.